UCLA health says hack exposed personal data on 4.5 million people

University of California (UCLA) Health, which runs four hospitals in the university's campuses, said its computer systems had been hacked and that data on as many as 4.5 million individuals could have been exposed. UCLA Health said on Friday it was working with the FBI and private computer forensic experts to look into the cyberattack.

UCLA Health detected suspicious activity in its network in October 2014 and began an investigation. Last May, it determined that the attackers had accessed parts of its network that contain personal information such as names, addresses, dates of birth, Social Security numbers, medical record numbers, Medicare or health plan ID numbers and some medical information.

"At this time, there is no evidence that the attacker actually accessed or acquired individuals' personal or medical information," UCLA Health said. "Because UCLA Health cannot conclusively rule out the possibility that the attackers may have accessed this information, however, individuals whose information was stored on the affected parts of the network are in the process of being notified."